Identification, characterization and hypolipidemic effect of novel peptides in protein hydrolysate from Protaetia brevitarsis larvae.

The proteins were mainly derived from Protaetia brevitarsis larval extracts obtained using two empty intestine methods (traditional static method: TSM or salt immersion stress method: SISM) and extraction solvents (water: W or 50 % water-ethanol: W:E), and the proteins were used as objects to investigate the effect of emptying intestine methods on hypolipidemic peptides. The results revealed that the F-2 fractions of protein hydrolysate had stronger in vitro hypolipidemic activity, with the peptides obtained by SISM possessing a stronger cholesterol micelle solubility inhibition rate, especially in SISM-W:E-P. Moreover, a total of 106 peptides were tentatively identified, among which SISM identified more peptides with an amino acid number < 8. Meanwhile, five novel peptides (YPPFH, YPGFGK, KYPF, SPLPGPR and VPPP) exhibited good hypolipidemic activity in vitro and in vivo, among which YPPFH, VPPP and KYPF had strong inhibitory activities on pancreatic lipase (PL) and cholesteryl esterase (CE), and KYPF, SPLPGPR and VPPP could significantly reduce the TG content in Caenorhabditis elegans. Thus, P. brevitarsis can be developed as a naturally derived hypolipidemic component for the development and application in functional foods.

Characterization of bioactives and in vitro biological activity from Protaetia brevitarsis larval extracts obtained by different pretreatment extractions.

Intestinal contents affect the characterization of edible insect bioactive compounds. Two empty intestine methods, namely, traditional static method (TSM) or salt immersion stress method (SISM), associated with extraction solvents water (W), 50 % water-ethanol (W:E) or 100 % ethanol (E), were used to obtain six Protaetia brevitarsis larval extracts. The total flavonoid content (TFC) in the W:E extracts was significantly higher than that in the W and E extracts, with TSM-W:E the highest (p < 0.05). The relative contents of 132 bioactive compounds, especially p-hydroxyphenylacetic acid, citric acid, and dehydroepiandrosterone, were different between TSM-W and SISM-W. TSM-W:E had significantly higher 2,2-diphenyl-1-picrylhydroxy· (DPPH) scavenging and pancreatic lipase (PL) inhibitory activity than SISM-W:E (p < 0.05). DPPH scavenging and PL inhibitory activities were highly correlated with TFC and carbohydrates, respectively. Thus, bioactive compounds in P. brevitarsis extracts can be obtained selectively using pretreatment methods, which might be beneficial for high-value utilization of P. brevitarsis.

Polymorphisms of the ICAM-1 exon 6 (E469K) are associated with differentiation of colorectal cancer.

BACKGROUND: Genetic factors are thought to play a role in development for colorectal carcinogenesis. ICAM-1 is a polymorphic gene, thus, the present study investigated the relationship between the polymorphisms of ICAM-1 and the susceptibility and phenotypical characteristics of colorectal cancer (CRC). METHODS: The polymorphisms at ICAM-1 exon 4 (G241R) and exon 6 (E469K) were detected by PCR with sequence-specific primers. The relationship between specific genotypes of ICAM-1 and differentiation of CRC was evaluated by the histological grade. RESULTS: We showed only GG genotype of ICAM-1 individuals in either CRC or normal controls. The KK genotype of ICAM-1 K469E was found more frequently than in the controls (P < 0.05). Patients with well-differentiated CRC displayed the KK more frequently than those of poor differentiation (P < 0.05). CONCLUSION: The findings indicate that polymorphisms of G241R are rare in Chinese population and that KK genotype of ICAM-1 K469E is significantly associated with well differentiation of CRC.